Open Access
Stable multi-wavelength erbium fiber ring laser with optical feedback for remote sensing
(IEEE / OSA, 2015) Díaz Lucas, Silvia; Leandro González, Daniel; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, we demonstrate a stable fiber sensing system for remote temperature measurements, where the sensing element is an array of four fiber Bragg gratings (FBGs) and sensor interrogation is achieved with a multi-wavelength erbium fiber ring laser. By introducing a feedback fiber loop in a fiber ring cavity, four laser emission lines were obtained simultaneously in single-longitudinal mode operation (SLM). The power instability obtained was lower than 0.5 dB with an optical signal-to-noise ratio (OSNR) higher than 50 dB for all the emitted wavelengths. The application of this system for remote temperature measurements has been demonstrated even though the SLM regime cannot be preserved.
Open Access
Ultra-long (290 km) remote interrogation sensor network based on a random distributed feedback fiber laser
(Optical Society of America, 2018) Miguel Soto, Verónica de; Leandro González, Daniel; López-Amo Sáinz, Manuel; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this work, an interferometric sensor has been interrogated 290 km away from the monitoring station, reaching the longest distance in fiber optic sensing up to date. This has been attained by employing a double-pumped random distributed feedback fiber laser as the light source for a fiber optic low-coherence interferometry scheme. Additionally, the capability of the system to achieve coherence multiplexing for ultra-long range measurements (up to 270 km) has been proved, without presenting crosstalk between the sensors. The use of coherence multiplexing together with a random distributed feedback fiber laser addresses two of the main limitations of long-range sensing setups: their limited multiplexing capability and the need to reach the maximum monitoring distance.
Open Access
L-band multiwavelength single-longitudinal mode fiber laser for sensing applications
(IEEE / OSA, 2012) Pérez Herrera, Rosa Ana; Ullán Nieto, Ángel; Leandro González, Daniel; Fernández Vallejo, Montserrat; Quintela, M. A.; Loayssa Lara, Alayn; López Higuera, José Miguel; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, a novel single-longitudinal-mode (SLM) four-wavelength laser configuration for sensing applications in the L-band is proposed and experimentally demonstrated. The sensor system presented here is based on ring resonators, and employs fiber Bragg gratings to select the operation wavelengths. The stable SLM operation is guaranteed when all the lasing channels present similar output powers. It is also experimentally demonstrated that when a SLMbehavior is achieved, lower output power fluctuations are obtained. Characterization of the lasing structure for temperature sensing is also shown.
Open Access
In-field torsion measurements on solar trackers using fiber optic sensors
(Optica, 2020) Leandro González, Daniel; Bravo Acha, Mikel; Júdez Colorado, Aitor; Mariñelarena Ollacarizqueta, Jon; Falcone Lanas, Francisco; Loayssa Lara, Alayn; López-Amo Sáinz, Manuel; Jiménez, S.; Achaerandio, Álvaro; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Gobierno de Navarra / Nafarroako Gobernua
In-field torsion measurements on solar trackers using fiber Bragg gratings are presented. 45 FBG sensors have been deployed in an operational solar energy plant to study the mechanical response of the structure to wind.
Open Access
Optical fiber sensors for asphalt structures monitoring
(Optica Publishing Group, 2016) Bravo Acha, Mikel; Rota Rodrigo, Sergio; Leandro González, Daniel; Loayssa Lara, Alayn; Urricelqui Polvorinos, Javier; Bravo Acha, A.; Bravo Navas, M.; Mitxelena, J. R.; Martínez Mazo, J. J.; López-Amo Sáinz, Manuel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
A novel optical fiber installation method was explored for asphalt monitoring. Glassfiber polymer encapsulated SMF was installed in the intermediate and surface layers in order to study the strain sensitivity with a distributed strain interrogator.
Open Access
High sensitive micro-displacement intensity fiber sensor by using a multiwavelength erbium doped fiber ring laser based on optical add-drop multiplexers
(SPIE, 2014-06-02) Pérez Herrera, Rosa Ana; Leandro González, Daniel; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, a wavelength division multiplexed fiber ring laser, based on optical add-drop multiplexers to interconnect intensity sensors has been experimentally demonstrated. Three different laser lines were obtained simultaneously all with an optical signal to noise ratio higher than 30dB. This proposed configuration is based on commercial devices and is adapted to the ITU channels normative. By using this configuration each sensor was associated with a different wavelength directly offered by each OADM and a reference wavelength was also included in order to distinguish between power variations induced by the transducer or to detect a fiber failure. This sensor system has been experimentally verified by using microbending sensors obtaining experimental slope sensitivity as good as -0.327dB/µm.
Open Access
Narrow-linewidth multi-wavelength random distributed feedback laser
(IEEE / OSA, 2015) Leandro González, Daniel; Rota Rodrigo, Sergio; Ardanaz, Diego; López-Amo Sáinz, Manuel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, narrow-band emission lines are generated by means of two random distributed feedback fiber laser schemes. Spectral line-widths as narrow as 3.2 pm have been measured, which significantly improves previous reported results. The laser is analyzed with the aim of obtaining a spectral line-width as narrow as possible. Additionally a variation of this setup for multi-wavelength operation is also validated. Both schemes present a simple topology that use a combination of phase-shifted fiber Bragg gratings and regular fiber Bragg gratings as filtering elements.
Open Access
Simultaneous measurement of strain and temperature using a unique LPG-coupled fibre laser scheme
(SPIE, 2014-06-02) Leandro González, Daniel; Ams, Martin; López-Amo Sáinz, Manuel; Sun, Tong; Grattan, Kenneth T. V.; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, we present and demonstrate a novel sensor system for simultaneous measurement of strain and temperature through a unique combination of a long period grating (LPG) and a fibre laser based on a fibre Bragg grating (FBG). In order to achieve this, a new erbium doped fibre laser (EDFL) structure is created, showing an optical signal-to-noise ratio (OSNR) of 55 dB and a peak power measured on the OSA between -5 and 0 dBm. The strain and the temperature variation applied on the FBG and the LPG can be monitored through both the fibre laser wavelength shift and the change of the power level of a unique emission line, both showing a clear linear behaviour.
Open Access
Simultaneous measurement of strain and temperature using a single emission line
(IEEE / OSA, 2015) Leandro González, Daniel; Ams, Martin; López-Amo Sáinz, Manuel; Sun, Tong; Grattan, Kenneth T. V.; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, we present and demonstrate a novel sensor system for simultaneous measurement of strain and temperature through a unique combination of a long period grating (LPG) and a fiber laser based on a fiber Bragg grating (FBG). In order to achieve this, a new erbium doped fiber laser (EDFL) structure is created, showing an optical signal-to-noise ratio (OSNR) of 55 dB and a peak power measured on the OSA between -5 and 0 dBm. The strain and the temperature information can be obtained by using a unique emission line through monitoring both the fiber laser wavelength shift and the change of the power level, both of which showing a clear linear behavior.
Open Access
Multicore fiber sensors for strain measurement towards traffic monitoring
(SPIE, 2023) Sánchez González, Arturo; Pradas Martínez, Javier; Corera Orzanco, Íñigo; Bravo Acha, Mikel; Leandro González, Daniel; Dauliat, Romain; Jamier, Raphael; Roy, Philippe; Pérez Herrera, Rosa Ana; López-Amo Sáinz, Manuel; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA06-2022
In this work, two new interferometric sensors based on multicore optical fibers for the measurement of strain with the ultimate goal of traffic monitoring are presented. The operating principle of each sensor relied on the monitoring of the phase shift difference accumulated between the supermodes of the structure of the multicore segment in a full round trip. The strain characterization for both sensors resulted in a linear response, with sensitivities of -4.073·10-3 rad/με and - 4.389·10-3 rad/με for the aligned and V-shaped cases respectively, and one-hour instabilities below 4.6·10-3 rad with a 95% confidence level. These results suggest its feasibility in applications requiring high sensitivities over very wide strain ranges, such as heavy-vehicle traffic monitoring. To corroborate the hypothesis, both sensors were integrated into the pavement and their response to the traffic was analyzed.